/Engine/Source/Editor/UnrealEd/Classes/ThumbnailRendering/ThumbnailManager.h
Registers a custom thumbnail renderer for a specific class
virtual void RegisterCustomRenderer ( [UClass](API\Runtime\CoreUObject\UObject\UClass) * Class, [TSubclassOf](API\Runtime\CoreUObject\Templates\TSubclassOf)< [UThumbnailRenderer](API\Editor\UnrealEd\ThumbnailRendering\UThumbnailRenderer) > RendererClass )